Currently available LED drivers and controllers include those that support a 0-10V control interface. These drivers and controllers are commonly used for dimming. FIG. 1 illustrates one example of a system using 0-10V control and includes a 0-10V controller or switch (e.g., a dimmer) 102, a driver 104, and an LED board 106. The driver provides a 0-10V control interface 108, which is a current limited voltage source. FIG. 1 illustrates the 0-10V control interface as providing a power signal to the controller (0-10 Control Power Signal) and receiving a 0-10V control signal (0-10 Control Regulated Signal) from the controller. The driver powers the LED board at a level that is based on the 0-10V control signal. For example, when the 0-10V control signal is 10V, then the driver powers the LED board so that it provides full light output. When the 0-10V control signal is 5V, then the driver powers the LED board so that it provides 50% light output.
Some systems include additional sensors or controls that may modify the 0-10V control signal provided to the driver (not shown). For example, an ambient light sensor may sense ambient light and based on the amount of sensed ambient light may increase or decrease the voltage on the 0-10V control signal so that the voltage seen by the driver is different than the voltage sent from the controller. Typically these sensors sense conditions at the system level and do not adequately account for conditions on the LED board or for differences between the LED boards.
Although FIG. 1 illustrates that the controller controls a single driver, which powers a single LED board, one controller can control multiple drivers and LED boards. If so, then the controller is connected to a second driver in a manner similar to that shown for the first driver and the second driver powers the second LED board. There can also be additional sensors or controls associated with the second driver similar to those described above for the first driver.